This disclosure relates generally to stereophony and specifically to determining a head-related transfer function (HRTF) using base stations.
A sound perceived at two ears can be different, depending on a direction and a location of a sound source with respect to each ear as well as on the surroundings of a room in which the sound is perceived. Humans can determine a location of the sound source by comparing the sound perceived at each ear. In a “surround sound” system a plurality of speakers reproduce the directional aspects of sound using HRTFs. An HRTF characterizes how an ear receives a sound from a point in space. The HRTF for a particular source location relative to a person is unique to each ear of the person (and is unique to the person) due to the person's anatomy (e.g., ear shape, shoulders, etc.,) that affects the sound as it travels to the person's ears.
Conventionally, HRTFs are determined in a sound dampening chamber for many different source locations (e.g., typically more than a 100 speakers) relative to a person. The determined HRTFs may then be used to generate a “surround sound” experience for the person. But the quality of the surround sound depends heavily on the number of different locations used to generate the HRTFs. Moreover, to reduce error, it is common to determine multiple HRTFs for each speaker location (i.e., each speaker is generating a plurality of discrete sounds). Accordingly, for high quality surround sound it takes a relatively long time (e.g., more than an hour) to determine the HRTFs as there are multiple HRTFs determined for many different speaker locations. Additionally, the infrastructure for measuring HRTFs sufficient for quality surround sound is rather complex (e.g., sound dampening chamber, one or more speaker arrays, etc.). Accordingly, conventional approaches for obtaining HRTFs are inefficient in terms of hardware resources and/or time needed.